<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8"/>
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no, viewport-fit=cover"/>
<meta name="description" content="Context menus implemented in HTML rather than as GoJS objects."/> 
<link rel="stylesheet" href="../assets/css/style.css"/> 
<!-- Copyright 1998-2021 by Northwoods Software Corporation. -->
<title>HTML Context Menu</title>
</head>

<body>
  <!-- This top nav is not part of the sample code -->
  <nav id="navTop" class="w-full z-30 top-0 text-white bg-nwoods-primary">
    <div class="w-full container max-w-screen-lg mx-auto flex flex-wrap sm:flex-nowrap items-center justify-between mt-0 py-2">
      <div class="md:pl-4">
        <a class="text-white hover:text-white no-underline hover:no-underline
        font-bold text-2xl lg:text-4xl rounded-lg hover:bg-nwoods-secondary " href="../">
          <h1 class="mb-0 p-1 ">GoJS</h1>
        </a>
      </div>
      <button id="topnavButton" class="rounded-lg sm:hidden focus:outline-none focus:ring" aria-label="Navigation">
        <svg fill="currentColor" viewBox="0 0 20 20" class="w-6 h-6">
          <path id="topnavOpen" fill-rule="evenodd" d="M3 5a1 1 0 011-1h12a1 1 0 110 2H4a1 1 0 01-1-1zM3 10a1 1 0 011-1h12a1 1 0 110 2H4a1 1 0 01-1-1zM9 15a1 1 0 011-1h6a1 1 0 110 2h-6a1 1 0 01-1-1z" clip-rule="evenodd"></path>
          <path id="topnavClosed" class="hidden" fill-rule="evenodd" d="M4.293 4.293a1 1 0 011.414 0L10 8.586l4.293-4.293a1 1 0 111.414 1.414L11.414 10l4.293 4.293a1 1 0 01-1.414 1.414L10 11.414l-4.293 4.293a1 1 0 01-1.414-1.414L8.586 10 4.293 5.707a1 1 0 010-1.414z" clip-rule="evenodd"></path>
        </svg>
      </button>
      <div id="topnavList" class="hidden lg:text-base sm:block items-center w-auto mt-0 text-white p-0 z-20">
        <ul class="list-reset list-none font-semibold flex justify-end flex-wrap sm:flex-nowrap items-center px-0 pb-0">
          <li class="p-1 sm:p-0"><a class="topnav-link" href="../learn/">Learn</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="../samples/">Samples</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="../intro/">Intro</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="../api/">API</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="https://www.nwoods.com/products/register.html">Register</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="../download.html">Download</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="https://forum.nwoods.com/c/gojs/11">Forum</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="https://www.nwoods.com/contact.html"
           target="_blank" rel="noopener" onclick="getOutboundLink('https://www.nwoods.com/contact.html', 'contact');">Contact</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="https://www.nwoods.com/sales/index.html"
           target="_blank" rel="noopener" onclick="getOutboundLink('https://www.nwoods.com/sales/index.html', 'buy');">Buy</a></li>
        </ul>
      </div>
    </div>
    <hr class="border-b border-gray-600 opacity-50 my-0 py-0" />
  </nav>
  <div class="md:flex flex-col md:flex-row md:min-h-screen w-full max-w-screen-xl mx-auto">
    <div id="navSide" class="flex flex-col w-full md:w-48 text-gray-700 bg-white flex-shrink-0"></div>
    <!-- * * * * * * * * * * * * * -->
    <!-- Start of GoJS sample code -->
    
    <script src="../release/go.js"></script>
    <div class="p-4 w-full">
  <style type="text/css">
    /* CSS for the traditional context menu */
    .menu {
      display: none;
      position: absolute;
      opacity: 0;
      margin: 0;
      padding: 8px 0;
      z-index: 999;
      box-shadow: 0 5px 5px -3px rgba(0, 0, 0, .2), 0 8px 10px 1px rgba(0, 0, 0, .14), 0 3px 14px 2px rgba(0, 0, 0, .12);
      list-style: none;
      background-color: #ffffff;
      border-radius: 4px;
    }

    .menu-item {
      display: block;
      position: relative;
      min-width: 60px;
      margin: 0;
      padding: 6px 16px;
      font: bold 12px sans-serif;
      color: rgba(0, 0, 0, .87);
      cursor: pointer;
    }

    .menu-item::before {
      position: absolute;
      top: 0;
      left: 0;
      opacity: 0;
      pointer-events: none;
      content: "";
      width: 100%;
      height: 100%;
      background-color: #000000;
    }

    .menu-item:hover::before {
      opacity: .04;
    }

    .menu .menu {
      top: -8px;
      left: 100%;
    }

    .show-menu, .menu-item:hover > .menu {
      display: block;
      opacity: 1;
    }
  </style>
  <script id="code">

  var myDiagram = null;

  function init() {
    if (window.goSamples) goSamples();  // init for these samples -- you don't need to call this
    var $ = go.GraphObject.make;  // for conciseness in defining templates

    myDiagram =
      $(go.Diagram, "myDiagramDiv",  // create a Diagram for the DIV HTML element
        {
          "undoManager.isEnabled": true
        });

    // This is the actual HTML context menu:
    var cxElement = document.getElementById("contextMenu");

    // an HTMLInfo object is needed to invoke the code to set up the HTML cxElement
    var myContextMenu = $(go.HTMLInfo, {
      show: showContextMenu,
      hide: hideContextMenu
    });

    // define a simple Node template (but use the default Link template)
    myDiagram.nodeTemplate =
      $(go.Node, "Auto",
        { contextMenu: myContextMenu },
        $(go.Shape, "RoundedRectangle",
          // Shape.fill is bound to Node.data.color
          new go.Binding("fill", "color")),
        $(go.TextBlock,
          { margin: 3 },  // some room around the text
          // TextBlock.text is bound to Node.data.key
          new go.Binding("text", "key"))
      );

    // create the model data that will be represented by Nodes and Links
    myDiagram.model = new go.GraphLinksModel(
      [
        { key: "Alpha", color: "#f38181" },
        { key: "Beta", color: "#eaffd0" },
        { key: "Gamma", color: "#95e1d3" },
        { key: "Delta", color: "#fce38a" }
      ],
      [
        { from: "Alpha", to: "Beta" },
        { from: "Alpha", to: "Gamma" },
        { from: "Beta", to: "Beta" },
        { from: "Gamma", to: "Delta" },
        { from: "Delta", to: "Alpha" }
      ]);

    myDiagram.contextMenu = myContextMenu;

    // We don't want the div acting as a context menu to have a (browser) context menu!
    cxElement.addEventListener("contextmenu", function(e) {
      e.preventDefault();
      return false;
    }, false);

    function hideCX() {
      if (myDiagram.currentTool instanceof go.ContextMenuTool) {
        myDiagram.currentTool.doCancel();
      }
    }

    function showContextMenu(obj, diagram, tool) {
      // Show only the relevant buttons given the current state.
      var cmd = diagram.commandHandler;
      var hasMenuItem = false;
      function maybeShowItem(elt, pred) {
        if (pred) {
          elt.style.display = "block";
          hasMenuItem = true;
        } else {
          elt.style.display = "none";
        }
      }
      maybeShowItem(document.getElementById("cut"), cmd.canCutSelection());
      maybeShowItem(document.getElementById("copy"), cmd.canCopySelection());
      maybeShowItem(document.getElementById("paste"), cmd.canPasteSelection(diagram.toolManager.contextMenuTool.mouseDownPoint));
      maybeShowItem(document.getElementById("delete"), cmd.canDeleteSelection());
      maybeShowItem(document.getElementById("color"), obj !== null);

      // Now show the whole context menu element
      if (hasMenuItem) {
        cxElement.classList.add("show-menu");
        // we don't bother overriding positionContextMenu, we just do it here:
        var mousePt = diagram.lastInput.viewPoint;
        cxElement.style.left = mousePt.x + 5 + "px";
        cxElement.style.top = mousePt.y + "px";
      }

      // Optional: Use a `window` click listener with event capture to
      //           remove the context menu if the user clicks elsewhere on the page
      window.addEventListener("click", hideCX, true);
    }

    function hideContextMenu() {
      cxElement.classList.remove("show-menu");
      // Optional: Use a `window` click listener with event capture to
      //           remove the context menu if the user clicks elsewhere on the page
      window.removeEventListener("click", hideCX, true);
    }
  }

  // This is the general menu command handler, parameterized by the name of the command.
  function cxcommand(event, val) {
    if (val === undefined) val = event.currentTarget.id;
    var diagram = myDiagram;
    switch (val) {
      case "cut": diagram.commandHandler.cutSelection(); break;
      case "copy": diagram.commandHandler.copySelection(); break;
      case "paste": diagram.commandHandler.pasteSelection(diagram.toolManager.contextMenuTool.mouseDownPoint); break;
      case "delete": diagram.commandHandler.deleteSelection(); break;
      case "color": {
        var color = window.getComputedStyle(event.target)['background-color'];
        changeColor(diagram, color); break;
      }
    }
    diagram.currentTool.stopTool();
  }

  // A custom command, for changing the color of the selected node(s).
  function changeColor(diagram, color) {
    // Always make changes in a transaction, except when initializing the diagram.
    diagram.startTransaction("change color");
    diagram.selection.each(function(node) {
      if (node instanceof go.Node) {  // ignore any selected Links and simple Parts
        // Examine and modify the data, not the Node directly.
        var data = node.data;
        // Call setDataProperty to support undo/redo as well as
        // automatically evaluating any relevant bindings.
        diagram.model.setDataProperty(data, "color", color);
      }
    });
    diagram.commitTransaction("change color");
  }
  window.addEventListener('DOMContentLoaded', init);
</script>

<div id="sample">
  <div style="display: inline-block;">
    <!-- We make a div to contain both the Diagram div and the context menu (such that they are siblings)
         so that absolute positioning works easily.
         This DIV containing both MUST have a non-static CSS position (we use position: relative)
         so that our context menu's absolute coordinates work correctly. -->
    <div style="position: relative;"  >
      <div id="myDiagramDiv" style="border: solid 1px black; width:400px; height:400px"></div>
      <ul id="contextMenu" class="menu">
        <li id="cut" class="menu-item" onclick="cxcommand(event)">Cut</li>
        <li id="copy" class="menu-item" onclick="cxcommand(event)">Copy</li>
        <li id="paste" class="menu-item" onclick="cxcommand(event)">Paste</li>
        <li id="delete" class="menu-item" onclick="cxcommand(event)">Delete</li>
        <li id="color" class="menu-item">Color
          <ul class="menu">
            <li class="menu-item" style="background-color: #f38181;" onclick="cxcommand(event, 'color')">Red</li>
            <li class="menu-item" style="background-color: #eaffd0;" onclick="cxcommand(event, 'color')">Green</li>
            <li class="menu-item" style="background-color: #95e1d3;" onclick="cxcommand(event, 'color')">Blue</li>
            <li class="menu-item" style="background-color: #fce38a;" onclick="cxcommand(event, 'color')">Yellow</li>
          </ul>
        </li>
      </ul>
    </div>

    <div id="description">
      <p>This demonstrates the implementation of a custom HTML context menu.</p>
      <p>For a light-box style HTML context menu implementation, see the <a href="htmlLightBoxContextMenu.html">LightBox Context Menu</a> sample.</p>
      <p>Right-click or tap-hold on a Node to bring up a context menu.
      If you have a selection copied in the clipboard, you can bring up a context menu anywhere to paste.</p>
    </div>
  </div>
</div>
    </div>
    <!-- * * * * * * * * * * * * * -->
    <!--  End of GoJS sample code  -->
  </div>
</body>
<!--  This script is part of the gojs.net website, and is not needed to run the sample -->
<script src="../assets/js/goSamples.js"></script>
</html>
